申请人发现在鹅同一生殖生理期处理6h，存在LPS间接作用抑制等级卵泡颗粒层P4合成的现象，但其作用机制不清楚。禽类卵泡颗粒细胞LHR-cAMP信号通路对P4合成至关重要。LPS可能影响了LH和炎性因子生成，间接通过颗粒细胞LHR-cAMP信号抑制P4合成限速酶表达，最终抑制P4合成。本项目拟进一步检测血液LH和炎性因子水平、垂体LHβ表达以及不同等级卵泡颗粒层LHR、炎性因子受体、cAMP信号和P4合成关键酶表达；再培养体内LPS处理的颗粒细胞和体外炎性因子处理的颗粒细胞，并梯度增强LHR-cAMP信号，检测P4合成能力，证明LHR-cAMP信号介导LPS间接作用抑制颗粒细胞P4合成；最后结合P4合成限速酶基因启动子区表观遗传修饰水平，揭示LPS间接作用抑制鹅等级卵泡颗粒细胞P4合成的分子机制。预期结果为预防LPS诱发的鹅卵巢功能紊乱提供理论依据。

We observed that P4 synthesis in goose hierarchiacal follicular granulose cell was indirectly inhibited at 6 h after lippolysaccharide (LPS) treatment during the same reproductive period. However, the underlying mechanisms are unknown. LHR-cAMP signaling pathway is essential for avian follicular granulose cell P4 synthesis. It is proposed that LPS inhibits expression of key enzymes associated with P4 synthesis through LH receptor signaling due to changed circulating LH and proinflammatory cytokines levels, which results in decreased P4 synthesis. In view of the above, this project planes to further investigate the plasma concentrations of LH and proinflammatory cytokines, expression level of LHβ in pituitary, and expression levels of LHR, proinflammatory cytokine receptors, and key enzymes associated with cAMP signaling pathway and P4 synthesis in hierarchical follicular granulosa layer. Furthermore, granulosa cells from goose hierarchiacal folicles treated by LPS for 0 and 6 h would be cultured with and without the addition of proinflammatory cytokine, respectively. The capacity of P4 synthesis in granulosa cells would be determined after gradually enhancing the LHR-cAMP signaling. These works will elucidate the LHR-cAMP signaling pathway in which LPS inhibits goose hierarchiacal follicular P4 synthesis. Finally, the molecular mechanisms of indirect inhibitory effect of LPS on goose hierarchiacal follicular P4 synthesis would be discovered according to the results of epigenetic modification of promoter region of key enzymes associated with P4 synthesis. This project will provide theoretical foundations for preventing ovarian dysfunction induced by gram-negative bacterium.